Oxiranes

ABSTRACT

There are described compounds of formula ##STR1## in which n is 0, 1 or 2, R 1  is a hydrocarbyl group optionally substituted with an optionally substituted phenyl group and containing from 5 to 30 carbon atoms, R 2  is optionally substituted phenyl or C 1-10  alkyl optionally substituted by one or more substituents selected from optionally protected hydroxyl, optionally protected carboxyl, nitrile, optionally protected tetrazolyl, --COR 6  where R 6  is C 1-4  alkyl, C 1-4  alkoxy, an optionally protected amino acid residue or --NR 2   7  where each R 7  is hydrogen or C 1-4  alkyl, and --NHR 8  where R 8  is hydrogen, a protecting group, an optionally protected amino acid residue, C 1-4  alkyl or --COR 9  where R 9  is C 1-4  alkyl or C 1-4  alkoxy, and R 3 , R 4  and R 5  are each selected from hydrogen, carboxyl, C 2-5  alkoxycarbonyl, C 1-4  alkyl, C 1-4  alkoxy, hydroxyl, optionally protected tetrazolyl, halo, trifluoromethyl, nitrile, nitro and --CONR 2   10  where each R 10  is hydrogen or C 1-4  alkyl; and salts thereof. The compounds are leukotriene antagonists.

This invention relates to novel compounds and their use aspharmaceuticals.

The compounds of the invention are of the formula ##STR2## in which n is0, 1 or 2, R¹ is a hydrocarbyl group optionally substituted with anoptionally substituted phenyl group and containing from 5 to 30 carbonatoms, R² is optionally substituted phenyl or C₁₋₁₀ alkyl optionallysubstituted by one or more substituents selected from optionallyprotected hydroxyl, optionally protected carboxyl, nitrile, optionallyprotected tetrazolyl, --COR⁶ where R⁶ is C₁₋₄ alkyl, C₁₋₄ alkoxy, anoptionally protected amino acid residue or --NR₂ ⁷ where each R⁷ ishydrogen or C₁₋₄ alkyl, and --NHR⁸ where R⁸ is hydrogen, a protectinggroup, an optionally protected amino acid residue, C₁₋₄ alkyl or --COR⁹where R⁹ is C₁₋₄ alkyl or C₁₋₄ alkoxy, and R³, R⁴ and R⁵ are echselected from hydrogen, carboxyl, C₂₋₅ akoxycarbonyl, C₁₋₄ alkyl, C₁₋₄alkoxy, hydroxyl, optionally protected tetrazolyl, halo,trifluoromethyl, nitrile, nitro and --CONR₂ ¹⁰ where each R¹⁰ ishydrogen or C₁₋₄ alkyl; and salts thereof.

The compounds of the invention, in unprotected form, have been shown tobe pharmacologically active in tests which demonstrate their antagonisteffect on leukotriene receptors and indicate their use in the treatmentof allergic disorders.

In the above general formula, the optionally substituted hydrocarbylgroup includes an optionally substituted alkyl group or optionallysubstituted alkenyl and alkynyl groups, the substituents on such groupsbeing phenyl and substituted phenyl. The hydrocarbyl group preferablycontains from 5 to 20 carbon atoms, for example from 10 to 20 carbonatoms and especially from 10 to 15 carbon atoms. When R¹ is alkyl it canbe branched or unbranched and is preferably one containing 10 to 15carbon atoms. When R¹ is alkenyl it can be branched or unbranchedpreferably containing 10 to 15 carbon atoms, such as for example 12 to15. The alkenyl group preferably contains 1 to 4 double bonds and canbe, for example, of the general formula

    R.sup.11 CH═CHCH═CH--

where R¹¹ is C₇₋₁₁ alkyl or CH₃ (CH₂)_(n) CH═CH--CH₂ --CH═CH-- where nis 0 to 4. It will be appreciated that such double bonds provideopportunities for cis-trans isomeric forms. Two especially preferredexamples of alkenyl groups are: ##STR3##

Where R¹ is alkynyl it can be branched or unbranched, and preferablycontains from 10 to 15 carbon atoms having 1 to 4 triple bonds. It is tobe understood that such alkynyl groups can also contain one or more, forexample, 1 to 3 double bonds in addition to its triple bond or bonds.

When R¹ is substituted hydrocarbyl it is substituted by an optionallysubstituted phenyl ring, preferably phenyl itself, or a phenyl groupsubstituted with one or more, preferably 1 to 3, substituents selectedfrom C₁₋₄ alkyl, especially methyl, C₁₋₄ alkoxy, especially methoxy andethoxy, hydroxy, nitro, cyano, halo, especially chloro, trifluoromethyl,carboxyl, tetrazolyl and --CONH₂. When R¹ is substituted with anoptionally substituted phenyl group it is preferably an alkenyl group.

It is preferred that R¹ is one of the above defined alkenyl groups.

With regard to R², this can be a C₁₋₁₀ alkyl group, preferably C₁₋₆alkyl, and optionally substituted by one or more, preferably 1 to 3,substituents as defined above. The substituent can be, --COR⁶ or --NHR⁸where R⁶ and R⁸ are amino acid residue. Such amino acid residues can beoptionally protected by a conventional protecting group and can bederived from any of the commonly occurring amino acids. In the case ofR⁶ the residue is preferably derived from glycine having the value--NHCH₂ COOH and in the case of R⁸ it is preferably derived fromaspartic acid or glutamic acid, having the values --COCH₂ CH(NH₂)COOHand --COCH₂ CH₂ CH(NH₂)COOH, respectively. Examples of the SR² groupinclude cysteinyl, cysteinylglycinyl and glutathionyl of formulae --SCH₂CH(NH₂)COOH, --SCH₂ CH(NH₂)CONHCH₂ COOH and ##STR4## respectively.

Preferably R² is an alkyl group substituted with 1 to 3 substituentsselected from carboxyl, nitrile, tetrazolyl, and --COR⁶ where R⁶ is--NR₂ ⁷ or C₁₋₄ alkoxy.

A particularly preferred value of R² is of the following formula:

    --(CH.sub.2).sub.x R.sup.12

where x is 1 to 5 and R¹² is carboxyl, nitrile, --CONH₂ or tetrazolyl.Most preferred are groups in which x is 2 and/or R¹² is carboxyl ortetrazolyl.

As mentioned above, R² can be optionally substituted phenyl and it canbe any of the values defined above when R¹ bears an optionallysubstituted phenyl group. Preferably the phenyl ring is substituted with1 to 3 substituents selected from carboxyl, tetrazolyl and CONH₂, andespecially a single carboxyl substituent.

As defined above, the groups R³, R⁴ and R⁵ can be hydrogen, carboxyl,C₂₋₅ alkoxycarbonyl, C₁₋₄ alkyl, C₁₋₄ alkoxy, hydroxyl, optionallyprotected tetrazolyl, halo, trifluoromethyl, nitrile, nitro and --CONHR₂¹⁰ where each R¹⁰ is hydrogen or C₁₋₄ alkyl. The tetrazolyl group ispreferably 1H-tetrazol-5-yl. Preferably there is a single substituent onthe phenyl ring and it is preferred that the substituent be nitrile,--CONH₂, tetrazolyl or carboxyl, acid substituents such as tetrazolyland carboxyl being best of all. Maximum biological activity is given bythe compounds in which the tetrazolyl or carboxyl group is attached atthe ortho or meta positions, and the most preferred groups are of theformula ##STR5##

Preferred compounds of formula (I) above are those in which n is 0.

In the above general formulae C₁₋₄ alkyl means a straight or branchedchain alkyl group, for example, methyl, ethyl, propyl, isopropyl, butyl,isobutyl and tertiary butyl, and is preferably methyl or ethyl.Similarly a C₁₋₄ alkoxy group is any such alkyl group attached throughoxygen to the appropriate moiety, and alkoxycarbonyl is a group of theform ROCO-- where R is a C₁₋₄ alkyl group as described above.

When substituents on the compound of formula (I) require protectionduring preparation they may be protected by conventional protectinggroups. Compounds with such protected carboxyl, amino acid residues,amino, hydroxyl and tetrazolyl groups are included in the scope of theinvention, through the preferred compounds with optimum biologicalproperties are the unprotected compounds derived from them.Carboxy-protecting groups are the well known ester forming groups usedfor the temporary protection of acidic carboxylic acid groups. Examplesof such groups which have general use are readily hydrolysable groupssuch as arylmethyl groups, haloalkyl groups, trialkylsilyl groups, alkylgroups, and alkenyl groups. Other carboxy protecting groups are thosedescribed by E. Haslam in Protective Groups in Organic Chemistry,Chapter 5. The amino-protecting groups that can be employed in thepreparation of the compounds of the invention are also conventionalprotecting groups. Illustrative of such groups are trihaloacetyl groupsespecially trifluoroacetyl. Such groups are well known in the art andare discussed, for example, in Peptide Synthesis by M. Bodansky, Y. S.Klausner and M. A. Ondetti, Second Edition (1976) John Wiley & Sons. Anyfree hydroxy groups present in the compound of the invention maylikewise be protected if needed. For example, a hydroxy group on the R²group of a compound of the formula I, can be protected with aconventional labile ether forming protecting group such as an etherformed with dihydropyran or methylvinyl ether, or by esters formed withthe lower alkyl carboxylic acids such as formic, acetic or propionic, orsuch halogenated acids, for example, chloroacetic acid, dichloroaceticacid or β,β-dichloropropionic acid. Furthermore, it is usually necessaryto protect any tetrazolyl group during the process of preparation, andsuitable and well known protecting groups for this purpose include thetrityl and benzhydryl groups formed by reaction with the appropriatehalide in the presence of base for example by reacting the tetrazolylreactant with trityl chloride and triethylamine.

When the compound of formula (I) bears an acidic function, base additionsalts can be prepared and these are to regarded as part of the presentinvention. Examples of such salts are those derived from ammoniumhydroxide and alkali and alkaline earth metal hydroxides, carbonates andbicarbonates, as well as salts derived from aliphatic and aromaticamines, aliphatic diamines and hydroxy alkylamines. Bases especiallyuseful in the preparation of such salts include ammonium hydroxide,potassium carbonate, sodium bicarbonate, calcium hydroxide, methylamine,diethylamine, ethylene diamine, cyclohexylamine and ethanolamine. Thepotassium and sodium salt forms together with other pharmaceuticallyacceptable salts are particularly preferred, but it is to be understoodthat other non-pharmaceutical salts are involved in the invention sincethey may be useful for identification, characterization or purificationof the free compound.

When the compound of formula (I) has a basic function acid additionsalts can be prepared and these are included in the present invention.Example of such salts are those derived from, preferably non-toxic,inorganic acids such as for example hydrochloric acid, nitric acid,phosphoric acid, sulphuric acid and nitric acid, as well as saltsderived from, preferably non-toxic, organic acids such as aliphaticmono- and di-carboxylic acids, phenyl-substituted alkanoic acids,hydroxyalkanoic acids, aromatic acids, and aliphatic and aromaticsulphonic acids.

It will be appreciated that the compounds of formula (I) possess chiralcentres at the carbon atoms bearing the hydroxyl and SR² groups and,accordingly, stereoisomeric forms exist R,R; S,S; R,S; and S,R. Otherchiral centres are also possible, depending on the nature of the varioussubstituents, which may lead to further sterioisomeric forms.Furthermore, as mentioned above, compounds containing R¹ alkenylsubstituents exhibit cis-trans isomeric forms. All such stereoisomers,and racemic mixtures thereof, are included within the scope of theinvention. Isomers can be isolated from racemic mixtures by conventionalmethods such as by the preparation of diastereoisomers with subsequentliberation of the enantiomers or, alternatively, can be prepared bymethods devised to give the pure isomer.

A particular group of compounds according to formula (I) above are thoseof the following formula ##STR6## in which R¹ is an optionallyunsaturated hydrocarbyl group containing from 5 to 30 carbon atoms, R²is C₁₋₁₀ alkyl optionally substituted by one or more substituentsselected from optionally protected hyroxyl, optionally protectedcarboxyl, --COR⁶ where R⁶ is C₁₋₄ alkoxy or an optionally protectedamino acid residue, and --NHR⁸ where R⁸ is hydrogen, a protecting group,a optionally protected amino acid residue, C₁₋₄ alkyl or --COR⁹ where R⁹is C₁₋₄ alkyl or C₁₋₄ alkoxy, and R³, R⁴ and R⁵ are each selected fromhydrogen, carboxyl, C₂₋₅ alkoxycarbonyl, C₁₋₄ alkyl, hydroxyl,tetrazolyl, halo, trifluoromethyl, nitrile and nitro; and salts thereof.

An especially preferred group of compounds of formula (I) above is ofthe formula ##STR7## in which R¹ is an alkenyl group containing 10 to 20carbon atoms, R² is of the formula --(CH₂)_(x) R¹² where x is 1 to 5 andR¹² is carboxyl, nitrile, --CONH₂ or tetrazolyl, and R³, R⁴ and R⁵ areselected from hydrogen, carboxyl, nitrile, --CONH₂ and tetrazolyl; andsalts thereof.

Of these compounds the most preferred are those in which R¹ is of theformula R¹¹ CH═CHCH═CH-- where R¹¹ is C₇₋₁₁ alkyl or CH₃ (CH₂)_(n)CH═CH--CH₂ --CH═CH-- and n is 0 to 4, R² is --(CH₂)_(x) R¹² where x is 1to 5 and R¹² is carboxyl, nitrile, --CONH₂ or tetrazolyl, R³ is nitrile,--CONH₂, tetrazolyl or carboxyl, the substituent preferably being at theortho or meta positions, and R⁴ and R⁵ are both hydrogen; salts thereof.

The invention also includes a process for producing a compound of theformula ##STR8## in which n is 0, 1 or 2, R¹ is a hydrocarbyl groupoptionally substituted with an optionally substituted phenyl group andcontaining from 5 to 30 carbon atoms, R² is optionally substitutedphenyl or C₁₋₁₀ alkyl optionally substituted by one or more substituentsselected from optionally protected hydroxyl, optionally protectedcarboxyl, nitrile, optionally protected tetrazolyl, --COR⁶ where R⁶ isC₁₋₄ alkyl, C₁₋₄ alkoxy, an optionally protected amino acid residue or--NR₂ ⁷ where each R⁷ is hydrogen or C₁₋₄ alkyl, and --NHR⁸ where R⁸ ishydrogen, a protecting group, an optionally protected amino acidresidue, C₁₋₄ alkyl or --COR⁹ where R⁹ is C₁₋₄ alkyl or C₁₋₄ -alkoxy,and R³, R⁴ and R⁵ are each selected from hydrogen, carboxyl, C₂₋₅alkoxycarbonyl, C₁₋₄ alkyl, C₁₋₄ alkoxy, hydroxyl, optionally protectedtetrazolyl, halo, trifluoromethyl, nitrile, nitro and --CONR₂ ¹⁰ whereeach R¹⁰ is hydrogen or C₁₋₄ alkyl; and salts thereof; which comprisesreacting a compound of formula ##STR9## in which R¹ is an optionallysubstituted alkenyl or alkynyl group, with a thiol of formula R² SH,optionally followed when it is desired to prepare a compound in which nis 1 or 2, by oxidation, or when it is desired to prepare a compound inwhich R¹ is optionally substituted alkyl, by reduction, or by removal ofany protecting groups, or by interconversion of an R², R³, R⁴ or R⁵group.

The reaction of compound of formula (II) with thiol is preferablycarried out in an inert organic solvent such as an alcohol, for examplemethanol, in the presence of a base such as a triethylamine and at atemperature of from 0° C. to 50° C. Thiol reactants containing potentialanion especially if it is sterically close to the thiol group are,desirably, protected before reaction.

When it is desired to prepare the sulphoxide compounds in which n is 1in formula (I) above, the corresponding sulphide in which n is 0 isreacted in substantially equivalent proportions with a suitableoxidising agent such as for example sodium periodate in an aqueus mediumsuch as aqueous methanol at a temperature of, for example, from 0° C. to50° C. The sulphone compounds in which n is 2 in formula (I) can beprepared by reacting the sulphide with an excess of oxidising agent suchas for example potassium persulphate, or by reacting the appropriatesulphoxide with an excess of oxidising agent, both reactions beingcarried out under similar conditions to those employed in thepreparation of the sulphoxide and preferably at a temperature of from 0°C. to 100° C.

It will be appreciated that it may be desired to remove any protectinggroups attached to the product of the reacton. Such reactions canreadily be carried out by use of a base in an inert organic solvent,such as for example, lithium hydroxide in tetrahydrofuran, or potassiumcarbonate in methanol, at a temperature of from 0° C. to 80° C., or byuse of acid such as hydrochloric acid for removal of protecting groupsfrom tetrazolyl, or by reducton in the case of protected amino groups,by well known procedures described for example in the authoritiesreferred to above.

Also it will be appreciated that one or more of the substituents on theR² group or R³, R⁴ and R⁵ groups can be interconverted. It is oftenpreferred, depending on the nature of the group, that suchinterconversions are carried out after reaction of compound of formula(II) with thiol.

For example, compounds in which R³, R⁴ or R⁵ is C₂₋₅ alkoxycarbonyl orin which R² bears such a group can be converted to the correspondingfree carboxyl by hydrolysis by means of base in an inert organicsolvent, such as for example, lithium hydroxide in tetrahydrofuran. Suchmethods are well known in the art. Conversely, compounds in which R³, R⁴or R⁵ is C₂₋₅ alkoxycarbonyl or R² has such a group can be prepared fromthe free acid by esterification of the free carboxyl group with theappropriate alcohol or by treatment with alkyl halide in the presence ofbase. Salts of the free acid can, of course, be prepared simply byreaction with alkali.

Compounds in which R³, R⁴ or R⁵ is --CONHR₂ ¹⁰ or R² bears a --CONR₂ ⁷group can be prepared by reacting a compound with an appropriatealkoxycarbonyl substituent with ammonia or the appropriate amine offormula R₂ ¹⁰ NH or R₂ ⁷ NH, respectively, or they can be prepared bythe reaction of an amine of formula R₂ ¹⁰

NH or R₂ ⁷ NH with the appropriate acyl chloride, which can in its turnbe derived from the free carboxyl derivative by the reaction of thionylchloride. Such reactions are well known in the art.

Compounds in which R³, R⁴ or R⁵ is a nitrile group or R² has such agroup can be prepared by dehydration of the appropriate amide (--CONH₂),a convenient dehydrating agent being, for example, a mixture oftriphenylphosphite and carbon tetrachloride.

Compounds in which R³, R⁴ or R⁵ is tetrazolyl or R² has such a group canbe prepared by reaction of the cyano derivative prepared as above with,for example sodium azide and ammonium chloride in dimethylformamide.Salts can be prepared from the tetrazolyl derivatives by the addition ofbase according to standard techniques.

It will be appreciated that the steps of reduction to provide thesaturated R¹ substituents, oxidation to provide sulphones andsulphoxides, removal of protecting group or interconversion of groups,can be carried out in whatever sequence best suits convenience and theaim of maximising yield.

The reactants of formula R² SH are known compounds or can be prepared bymethods of a type well known in the art. When they bear amino, carboxylor hydroxyl groups the reaction may benefit in yield if these groups arefirst protected, but such initial protection is by no means necessary inall cases.

Compounds of formula (II) in which R¹ is optionally substituted alkenylor alkynyl are novel and are included as part of the present invention.They may be prepared by the Wittig reaction of a phosphonium salt offormula R¹³ CH₂ P⁺ Ph₃ Br⁻, R¹³ being an appropriate optionallysubstituted alkyl, alkenyl or alkynyl group, in the presence of a basesuch as butyl lithium, with an aldehyde of formula (III) or (IV)##STR10## The reaction is generally carried out in a inert organicsolvent such as for example, tetrahydrofuran, at a temperature of from-80° C. to 0° C.

Compounds of formula (III) may be prepared from known intermediates by,for example, two principal routes. Firstly, they may be prepared, asracemic mixtures, by oxidation with, for example, hydrogen peroxide andsodium hydrogen carbonate in methanolic solution, of an aldehyde of theformula ##STR11## and, in its turn, aldehyde of formula (III) may beconverted to one of formula (IV) by reaction withformylmethylenetriphenylphosphorane.

Alternatively, the compounds of formula (III) may be prepared byoxidation of an epoxy alcohol of the formula ##STR12## with an oxidisingagent such as, for example, chromium trioxide in pyridine. Compounds offormula (V) can be prepared in stereospecific form and since the stericconfiguration is retained on oxidation to provide the aldehyde offormulae (III) and, ultimately, of formula (IV), this route can beemployed to provide stereospecific compounds of formula (I).

Compounds of formula (V) are prepared from the allyl alcohol ##STR13##using as epoxidising agent a reagent such as titaniumisopropoxide-t-butyl peroxide in the presence of L or D diethyl tartratewhich yields the S,S or R,R epoxide with the above E olefin. When the Zolefin is used as starting material, the appropriate S,R and R,Sstereosisomers result. Compounds of formula (VI) can be prepared fromthe appropriate benzaldehyde via a sequence of reactions involvingreaction with malonic acid to provide the cinnamic acid derivative,treatment with oxalyl chloride to give the acid chloride, and reductionwith a reagent such as lithium tri-t-butoxyaluminohydride.

Compounds of formula (I) in which R¹ is alkyl, that is, a saturatedgroup can be prepared preferably by hydrogenation of the appropriatecompound in which R¹ is alkenyl or alkynyl, with, for example, hydrogenand a heavy metal catalyst such as PtO₂ or Pd/carbon or other catalyticsystems, preferably at a temperature of from 0° C. to 100° C. and in aninert organic solvent such as for example ethanol.

The following scheme gives examples of the way in which preferredcompounds of the invention may be prepared: ##STR14##

The compounds of the present invention are pharmacologically active,being leukotriene antagonists as shown by the in vitro test on guineapig ileum segments at concentrations of from 10 ng to 50 μg, accordingto the method of Schild (1947) Brit. J. Pharm. 2, 197-206 (theunprotected compounds of formula (I) described in the following Examplesexhibited an IC₅₀ against LTD₄ of less than 10⁻⁵ molar). Also compoundsof the invention are active in the in vivo Guinea Pig Pulmonary FunctionTest of Austin and Drazen (1974) J. Clin. Invest. 53 1679-1685 atintravenous dosage levels of from 0.05 μg to 5.0 mg/kg and in a modified"Herxheimer" test (Journal of Physiology (London) 117 251 (1952)) atdoses of from 25 to 200 mg/kg. The "Herxheimer" test is based on an LTD⁴-- induced bronchospasm in guinea pigs which closely resembles anasthmatic attack in man.

The compounds are accordingly indicated for therapeutic use in thetreatment of diseases in which leukotrienes are implicated. Theseinclude allergic reactions of the pulmonary system in which leukotrienesare thought to be casual mediators of bronchospasm, for example, inallergic lung disorders such as extrinsic asthma and industrial asthmassuch as Farmers lung and Pigeon Fanciers lung, and in other inflammatorydisorders, for example, associated with acute or chronic infectionsdiseases such as allergic skin diseases, ectopic and atopic eczemas,psoriasis, contact hypersensitivity and angioneurotic oedema, bronchitisand crystic fibrosis and rheumatic fever.

Thus the invention also includes a pharmaceutical composition comprisinga pharmaceutically acceptable diluent or carrier in association with acompound of formula (I) in unprotected form; or a pharmaceuticallyacceptable salt thereof.

The compounds may be administered by various routes, for examples by theoral or rectal route, topically or parenterally, for example byinjection, and especially by inhalation, being usually employed in theform of a pharmaceutical composition. Such compositions are prepared ina manner well known in the pharmaceutical art and normally comprises atleast one active compound. In making the compositions of the presentinvention, the active ingredient will usually be mixed with a carrier,or diluted by a carrier, and/or enclosed within a carrier which may, forexample, be in the form of a capsule, sachet, paper or other container.When the carrier serves as a diluent, it may be a solid, semi-solid, orliquid material which acts as a vehicle, excipient or medium for theactive ingredient. Thus, the composition may be in the form of tablets,lozenges, sachets, cachets, elixirs, suspensions, aerosols (as a solidor in a liquid medium), ointments containing for example up to 10% byweight of the active compound, soft and hard gelatin capsules,suppositories, injection solutions and suspensions and sterile packagedpowders. For administration by inhalation, particular forms ofpresentation include aerosols, atomisers and vaporisers.

Some examples of suitable carriers are lactose, dextrose, sucrose,sorbitol, mannitol, starches, gum acacia, calcium phosphate, alginates,tragacanth, gelatin, syrup, methyl cellulose, methyl- andpropyl-hydroxybenzoate, talc, magnesium stearate and mineral oil. Thecompositions of the invention may, as is well known in the art, beformulated so as to provide quick, sustained or delayed release of theactive ingredient after administration to the patient.

Where the compositions are formulated in unit dosage form, it ispreferred that each unit dosage form contains from 5 mg to 500 mg, forexample, from 25 mg to 200 mg. The term "unit dosage form" refers tophysically discrete units suitable as unit dosages from human subjectsand animals, each unit containing a predetermined quantity of activematerial calculated to produce the desired therapeutic effect, inassociation with the required pharmaceutical carrier.

The active compounds are effective over a wide dosage range and, forexample, dosages per day will normally fall within the range of from 0.5to 300 mg/kg, more usually in the range of from 5 to 100 mg/kg. However,it will be understood that the amount administered will be determined bythe physician in the light of the relevant circumstances including thecondition to be treated, the choice of compound to be administered andthe chosen route of administration, and therefore the above dosageranges are not intended to limit the scope of the invention in any way.

The invention is illustrated by the following Examples. The structure ofthe compounds prepared was confirmed by I.R. and/or n.m.r. and/or massspectra and the purity of the product was checked in most cases by HPLC.The involatile products were examined by mass spectrometry using thefast atom bombardment (FAB) technique in the negative ion mode.Significant [M--H]⁻ ions (and characteristic fragment ions) wereobserved.

EXAMPLE 1

(a) 3-Carboxycinnamaldehyde, methyl ester

3-Carboxybenzaldehyde methyl ester (16.4 g) was dissolved in toluene(125 ml) and crystalline formylmethylene triphenylphosphorane (30.4 g)added with stirring under nitrogen. The mixture was brought to 100° C.and stirred for 4-5 hours. The dark straw coloured solution wasevaporated in vacuo and the residue extracted with diethyl ether. Theinsoluble triphenylphosphine oxide was removed by filtration and thedark yellow filtrate was concentrated in vacuo and chromatographed onsilica gel using diethylether/n-hexane 50/50 v/v as developing solvent.The required compound was obtained as a pale yellow crystalline solid.m.p. 86°-87° C.

(b) 3-(2-Formyl-1,2-oxido-ethyl)benzoic acid, methyl ester

3-Carboxycinnamaldehyde methyl ester (400 mg) was dissolved in methanol(12 ml) and added dropwise to a stirred solution of sodium bicarbonate(640 mg) and 28% hydrogen peroxide (1.6 ml) in water (24 ml). After theaddition was complete the mixture was stirred for 11/2 hours at roomtemperature. At this point TLC showed absence of starting aldehyde. Thehazy solution was extracted via dichlormethane (3×10 ml) and evaporatedin vacuo to give a nearly colourless oil (453 mg) mainly as the requiredaldehyde hydrate. Azeotropic distillation of this product from benzeneled to the title compound as a nearly colourless oil (340 mg) whichreadily crystallised on storage in the freezer.

(c) 3-(4-Formyl-1,2-oxido-but-3(E)-enyl)benzoic acid, methyl ester

The product of (b) was dissolved in benzene (40 ml) and crystallineformylmethylenetriphenylphosphorane (2 g) was added and the mixturestirred at room temperature under nitrogen for 2 hours. The benzene wasevaporated in vacuo and the residue extracted via diethylether to removeinsoluble triphenylphosphine oxide. The ether extract was evaporated andthe residue dissolved in a little diethylether/n-hexane, 50/50 v/v, andchromatographed on silica gel using the same solvent mixture fordevelopment. The fractions containing the title compound were bulked andevaporated to give the compound as a pale yellow oil.

(d) 3-(1,2-Oxido-pentadeca-3(E),5(Z)-dienyl)benzoic acid, methyl ester

n-Decyltriphenylphosphonium bromide (2.45 g) was dissolved in drytetrahydrofuran (50 ml), stirred under nitrogen and cooled to -78° C.Butyl lithium (1.55M solution in hexane, 3.4 ml) was added graduallywith immediate formation of and orange yellow colour. After 15 minutes asolution of the product from (c) in tetrahydrofuran (5 ml) was addedrapidly and the solution kept at -78° C. for 20 minutes, then allowed tocome slowly to room temperature. The solution was evaporated in vacuoand the residue extracted with diethylether/n-hexane 50/50 v/v. Thesolvent extract was concentrated and chromatographed on silica gel usingthe same solvent mixture for development. The title compound wasobtained as a colourless oil crystallizing on refrigeration.

(e)Rel(1R,2S)-3-(2-S-cysteinyl-1-hydroxypentadeca-3(E),5(Z)-dienyl)benzoicacid

The compound from (d) was reacted under nitrogen with a solution ofN-trifluoroacetylcysteine methyl ester (0.88 g) and triethylamine (1.1ml) in dry methanol (4.5 ml) at room temperature for 24 hours. Afterthis time the bulk of the starting epoxide had disappeared as indicatedby TLC.

The solution was evaporated in vacuo, then dissolved in a littlediethylether/n-hexane 50/50 v/v and chromatographed on silica geldeveloping at first with the same solvent mixture to remove traceamounts of the starting epoxide, then with diethylether to give thefully protected version of the title compound as a very pale strawcoloured oil. The product was dissolved in tetrahydrofuran (7 ml) andlithium hydroxide solution (1M, 8 ml) added, followed by additionalwater to give a hazy solution. After 3 days the hydrolysis wasincomplete, and further lithium hydroxide solution (4 ml) was added.After further 4 days the clear solution at pH ca 11 was extracted withdiethylether. The residual aqueous phase was then carefully adjusted topH 3.5-4 (dilute hydrochloric acid) then extracted several times withdichloromethane/methanol (3/1 v/v). The bulked organic phase wascarefully evaporated in vacuo to give the title compound initially apale straw coloured oil which gradually turned to a brittle solid.

The following compound was similarly prepared.Rel-(1R,2S)-3-(2-S-cysteinylglycinyl-1-hydroxypentedeca-3(E),5(Z)-dienyl)benzoicacid obtained as a light straw coloured oil.

EXAMPLE 2

(A) 3-Methoxycarbonylcinnamic acid

3-Carboxybenzaldehyde methyl ester (82 g) was dissolved in dry pyridine(250 ml) and malonic acid (52 g) added to the stirred solution.Piperidine (5 ml) was then added and the solution slowly heated toreflux. There was a slightly exothermic reaction accompanied by theevolution of carbon dioxide. After refluxing the solution for 1 hour anadditional portion of malonic acid (25.1 g) was added. The solution wasthen refluxed for a further 30 minutes before being cooled and added toice and 5M hydrochloric acid (1 liter). The resultant white solid wasfiltered off and washed with water before being dried in vacuo at 50° C.for 2 days. The crude product was then recrystallized from glacialacetic acid to give colourless plates, m.p. 189°-190° C. exclusively theE isomer.

(b) (E)-3-Methoxycarbonylcinnamyl chloride

Oxalyl chloride (13.9 g) was added to a stirred suspension of3-methoxycarbonylcinnamic acid (20.6 g) in dry ether (200 ml) and then 1drop of DMF was added to catalyse the reaction. After being stirred for1 hour at room temperature all the solid and dissolved and the solutionwas evaporated to dryness to yield the white crystalline acid chloridem.p. 70°-71° C.

(c) (E)-3-Methoxycarbonylcinnamyl alcohol

3-Methoxycarbonylcinnamyl chloride (24 g) was dissolved in drytetrahedrofuran and then this solution added to lithiumtri-tert-butoxyaluminohydride (63.5 g) dissolved in tetrahydrofuran (250ml) at -78° C. The resultant clear solution was stirred at -78° C. for30 minutes then it was added to ice and 2M hydrochloric acid (750 ml).The two phase mixtures was extracted 4 times with dichloromethane. Afterdrying the dichloromethane was evaporated to yield the title compound asa pale yellow oil.

(d) (E)-3-(3-Hydroxy-1,2-oxidopropyl)benzoic acid methyl ester

3-Methoxycarbonylcinnamyl alcohol (1.92 g) was dissolved indichloromethane (50 ml), cooled to 0° C. and metachloroperoxybenzoicacid (1.72 g) in dichloromethane 10 ml was added to the cooled solutiondropwise. The temperature of the reaction mixture was then allowed torise to room temperature. After 2 hours the meta-chlorobenzoic acid wasfiltered off and the solution washed with saturated sodium bicarbonatesolution twice. After drying evaporation of the dichloromethane layeryielded the title compound as a colourless oil.

(e) (Alternative Method)

(1S,2S) 3-(3-Hydroxy-1,2-oxidopropyl)benzoic acid, methyl ester

Titanium tetra-isopropoxide (1.3 ml) was dissolved in drydichloromethane (12 ml) and the stirred solution cooled to -60°° C.L-Diethyl tartrate, (6.0 mM) was then added and the solution allowed towarm to -20° C. and stirred for a further 10 minutes.3-Methoxycarbonylcinnamyl alcohol (960 mg) was then added. Finally a 3Msolution of tert-butyl hydroperoxide (6 ml) in 1,2-dichloroethane wasadded and the solution stored at -18° C. for 16 hours. Ether (15 ml) wasthen added to the reaction mixture followed by a saturated solution ofaqueous sodium sulphate (2 ml). The mixture was stirred at roomtemperature for 1 hour and filtered through celite. Toluene (100 ml) wasadded to the solution and it was evaporated to afford a colourless oilwhich was chromatographed on a silica column eluted with ether. Thediethyl tartrate eluted first followed by the title compound which wasobtained after evaporation of solvent as a colourless oil.

(f) 3-(2-Formyl-1,2-oxidoethyl)benzoic acid, methyl ester

Chromium trioxide (2.5 g) was added to a solution of pyridine (3.9 g) indichloromethane (100 ml) at 7° C. The temperature of the stirredsolution was allowed to rise to 14° C. and3(3-hydroxy-1,2-oxidopropyl)benzoic acid methyl ester (1.04 g) was addedin dichloromethane (2 ml). The solution darkened and a black oil cameout of solution. After 30 minutes at 22° C. the dichloromethane layerwas decanted off and filtered through Fluorosil. Upon evaporation thissolution yielded the title compound as a colourless oil.

(g) Rel(1R,2S)-3-(2-S-cysteinyl-1-hydroxypentadeca-3(E),5(Z)-dienyl)benzoicacid

The above compound was prepared from the compound of step (f) above bythe process described in steps (c), (d) and (e) of Example 1.

EXAMPLE 3

(a) Rel(1R,2S)-3-[2-(2-carboxyethylthio)-1-hydroxypentadec-3(E),5(Z)-dienyl]benzoicacid dimethyl ester

Methyl 3-mercaptopropionate (240 mg) was dissolved in dry methanol (3ml). Triethylamine (250 μl) was then added and the resultant solutionadded to 3-(1,2-oxidopentadeca-3(E),5(Z)-dienyl)benzoic acid methylester (712 mg). The resultant clear solution was then stored at 40° C.for 16 hours after which time it was evaporated to dryness andchromatographed on a silica column eluted with ether. The title compoundwas obtained as a colourless oil.

(b) Rel(1R,2S)-3-[2-(2-carboxyethylthio)-1-hydroxypentadec-3-(E),5(Z)-dienyl]benzoicacid

Rel(1R,2S)-3[2-(2-carboxyethylthio)-1-hydroxypentadec-3(E),5(Z)-dienyl]benzoicacid dimethyl ester (476 mg) was dissolved in tetrahydrofuran (10 ml)and a 1M lithium hydroxide solution (3 ml) was added to it. The mixturewas then stirred at room temperature for 2 days, the pH of the solutionwas then adjusted to 4 using dilute hydrochloric acid. Finally thissolution was extracted four times with dichloromethane which, afterdrying (MgSO₄) and evaporation, yielded the title compound as anoff-white solid, m.p. 87°-90° C.

EXAMPLE 4

(a) (1S,2S)-3-(1,2-Oxidopentadeca-3-(E),5(Z)-dienyl)benzoic acid

The above compound was prepared from the product of Example 2(e) by theprocesses described in Examples 2(f), 1(c) and 1(d). MS M⁺ 356.

(b)(1S,2R)-3-[2-(2-Carboxyethylthio)-1-hydroxy-pentadeca-3(E),5(Z)-dienyl]benzoicacid, dimethyl ester

The chiral epoxide prepared as described in step (a) was reacted by theprocess described in Example 3(a) to give the little compound as a paleoil. MS (FAB)M⁺ 477

(c)(1S,2R)-3-[2-(2-Carboxyethylthio)-1-hydroxy-pentadeca-3(E),5(Z)-dienyl]benzoicacid

The diester was hydrolysed by the method described in Example 3(b) togive the title compound as a white solid, m.p. ca 50° C., [α]_(D) +50.1°(c=2.3, MeOH), MS (FAB) [M--H]⁻ 447

EXAMPLE 5

(1R,2S)-3-[2-(2-Carboxyethylthio)-1-hydroxy-pentadeca-3(E),5(Z)-dienyl]benzoicacid

1R,2R)-3-(3-Hydroxy-1,2-oxidopropyl)benzoic acid, methyl ester wasprepared by the method described in Example 2(e) using D(-) diethyltartrate in place in the L(+) isomer. This epoxide was then reacted bythe processes described in Examples 2(f), 1(c), 1(d), 3(a) and 3(b) togive the title compound as a pale oil.

EXAMPLE 6

(a) (E)-2-Methoxycaronylcinnamyl alcohol

2-Methoxycarbonylcinnamic acid, m.p. 176° C., was prepared by the methoddescribed in Example 2(a) and converted to the acid chloride, m.p.75°-80° C., by the method described in Example 2(b). A solution of thisacid chloride (15.5 g) in ether (250 ml) was added to a stirredsuspension of sodium borohydride on alumina (60 g--prepared by additionof a solution of 1 part of sodium borohydride in 2 parts of water to 10parts of alumina, with cooling, followed by drying under vacuum) inether (360 ml). The mixture was stirred for 2 hours at room temperatureand filtered. The filtrate was washed with 10% sodium carbonatesolution, then with saturated sodium chloride solution, dried andevaporated to yield the title compound as a colourless oil.

(b) (E)-2-(3-Hydroxy-1,2-oxidopropyl)benzoic acid, methyl ester

Oxidation of (E)-2-methoxycarbonylcinnamyl alcohol withmeta-chloroperoxybenzoic acid as described in Example 2(d) followed bychromatography of the crude product on a silica column eluted with 2:1ether:hexane gave the title compound as a pale oil.

(c)3-[1-(2-Methoxycarbonylethylthio)-tetradec-2(E),4(Z)-dienyl]-1,3-dihydro-isobenzofuran-1-one2-(4-Formyl-1,2-oxidobut-3(E)-enyl)benzoic acid methyl ester, m.p. <50°C. was prepared from the compound of step (b) above by the processesdescribed in Examples 2(d), 2(f) and 1(c). Further reaction of thiscompound by the methods described in Examples 1(d) and 3(a) gave as themajor product the lactone title compound.

(d) Rel(1R,2S)-2-[2-(2-Carboxyethylthio)-1-hydroxypentadeca-3(E),5(Z)-dienyl]benzoicacid, disodium salt

A solution of3-[1-(2-methoxycarbonylethylthio)-tetradeca-2(E),4(Z)-dienyl]-1,3-dihydro-isobenzofuran-1-one(115 mg) in tetrahydrofuran (1 ml) and 0.5M sodium hydroxide solution(0.96 ml) was stirred at room temperature for 16 hours. The solution wasevaporated and the residue was washed with ether to leave the titlecompound as a viscous gum.

EXAMPLE 7

(a) 9-Bromo-2-methyl-4-decene

n-Butyl lithium (1.5M solution in hexane 6.8 ml) was added to a stirredsuspension of (3-methylbutyl)-triphenylphosphonium bromide (4.1 g) indry tetrahydrofuran (50 ml) at -60° C. under nitrogen. The dark mixturewas stirred for 40 minutes at -70° C. then a solution of 6-bromohexanal(1.8 g) in dry tetrahydrofuran (6 ml) was added. The pale mixture wasstirred for a further 1 hour at -70° C. then evaporated under vacuum.The residue was extracted with ether and the extract was evaporated to apale oil which was chromatographed on silica gel, eluting with 1:1ether:hexane, to give the title compound as a colourless oil. MS M⁺232/234.

(b) (9-Methyl-6-decenyl)-triphenylphosphonium bromide

A solution of 9-bromo-2-methyl-4-decene (0.9 g) and triphenylphosphine(1.5 g) in xylene (50 ml) was heated under reflux for 4 days. Themixture was cooled, the supernatant was decanted and the residue waswashed with ether and dried under vacuum to give the title compound as apale gum.

(c) (1S,2S)-3-(4-Formyl-1,2-oxidobut-3(E)-enyl)benzoic acid methyl ester

This compound was prepared from the product of Example 2(e) by theprocess described in Examples 2(f) and 1(c).

(d)(1S,2R)-3-[2-(2-Carboxyethylthio)-1-hydroxy-14-methylpentadeca-3(E),5(Z),11(Z)-trienyl]benzoicacid

The above compound was prepared from the compounds of steps (b) and (c)above by the processes described in Examples 1(d), 3(a) and 3(b). MS(FAB) [M--H] 459

EXAMPLE 8

(A) 1-Bromo-9-methyldecane

A solution of 9-bromo-2-methyl-4-decane (1.0 g) in ethanol (40 ml) washydrogenated for 20 minutes at 60 p.s.i. over platinum oxide (10 mg).The catalyst was filtered off and the filtrate was evaporated to givethe title compound as a pale oil.

(b) (9-Methyldecyl)-triphenylphosphorium bromide

A solution of 1-bromo-9-methyldecane (1.0 g) and triphenylphosphine (1.7g) in xylene (50 ml) was heated under reflux for 24 hours. The mixturewas cooled, the supernatant was decanted and the residue was washed withether and further dried by addition of benzene and evaporation to givethe title compound as a pale gum.

(c)(1S,2R)-3-[2-(2-Carboxyethylthio)-1-hydroxyl-14-methylpentadeca-3(E),5(Z)-dienyl]benzoicacid

The above compound was prepared from the compound of step (b) above and(1S,2S)-3-(4-formyl-1,2-oxidobut-3(E)-enyl) benzoic acid methyl ester(Example 7(c)) by the processes described in Examples 1(d), 3(a) and3(b). MS (FAB) [M--]⁻ 461

EXAMPLE 9

(1S,2R)-3-[2-(2-Aminocarbonylethylthio)-1-hydroxypentadeca-3(E),5(E)-dienyl]benzamide

A solution of(1S,2R)-3-[2-(2-carboxyethylthio)-1-hydroxypentadeca-3(E),5(Z)-dienyl]benzoicacid, dimethyl ester (50 mg) in methanolic ammonia solution (2 ml) wasstored at 50° C. in a sealed bottle for 3 weeks. The brown solution wasevaporated and the residue was purified by preparative reverse phaseHPLC to give the title compound as a pale solid, m.p. 83°-84° C. MS(FAB) [M--H]⁻ 445.

EXAMPLE 10

(a) 3-Cyanocinnamic acid

3-Cyanobenzaldehyde was reacted with malonic acid by the methoddescribed in Example 2(a) to give the title product, m.p. ca 240° C.

(b) 3-Aminocarbonylcinnamic acid

A solution of 3-carboxymethylcinnamic acid (427 g) (Example 2(a)) indimethyl formamide (4.25 l) and aqueous ammonia (specific gravity 0.88,8.5 l) was stored at room temperature for 4 days, concentrated to call11 l, and then treated with ice (8 kg) and concentrated hydrochloricacid (1 l). The precipitated title product was washed with water anddried, m.p. >260° C.

(c) 3-Cyanocinnamic acid (Alternative method)

Phosphorus oxychloride (746 ml) was added to a stirred suspension of3-aminocarbonylcinnamic acid (765 g) in dimethyl formamide (7.65 l). Theresulting solution was heated at 70°-80° C. for 50 minutes, cooled to50°-60° C., and poured onto ice (40 l) to precipitate the title compoundwhich was washed with water and dried, m.p. 242° C.

(d) 3-Cyanocinnamyl alcohol

The acid of steps (a) and (c) above was convered to the alcohol by theprocess described in Example 6(a) giving the title compound as a lowmelting white solid.

(e)(1S,2R)-3-[2-(2-Carboxyethylthio)-1-hydroxy-pentadeca-3(E),5(Z)-dienyl]benzonitrile,methyl ester

The above compound was prepared from the compound of step (d) above bythe process described in Examples 2(e), 2(f), 1(c), 1(d) and 3(a).

(f)(1S,2R)-3-[2-(2-Carboxyethylthio)-1-hydroxypentadeca-3(E),5(Z)-dienyl]benzonitrile

A solution of the methyl ester (step (e)) (950 mg) in methanol (200 ml)and 0.2M potassium carbonate solution (95 ml) was stirred at roomtemperature for 16 hours, concentrated to 70 ml, diluted with water (50ml) and washed with ether (50 ml). The aqueous phase was acidified topH3 and extracted with dichloromethane (3×50 ml). The extract was driedand evaporated to give the title product as a pale gum. MS(FAB) [M--H]428.

EXAMPLE 11

(1S,2R)-5-{3-[2-(2-Carboxyethylthio)-1-hydroxy-pentadeca-3(E),5(Z)dienyl]phenyl}-1H-tetrazole

A stirred suspension of ammonium chloride (5 g) and sodium azide (5 g)in a solution of(1S,2R)-3-[2-(2-carboxyethylthio)-1-hydroxy-pentadeca-3(E),5(Z)-dienyl]-benzonitrile(Example 10, 780 mg) in dimethyl formamide (25 ml) was heated at100°-105° C. for 12 hours. The dark mixture was filtered and thefiltrate was diluted with M hydrochloric acid (250 ml) and extractedwith dichloromethane (3×150 ml). The extract was washed with water,dried and evaporated to give a dark oil containing the 3(E),5(Z) and3(E),5(E) isomers in the ratio 30:70. The isomers were separated bypreparative reverse phase HPLC to give the title compound as a crispsolid.

EXAMPLE 12

(a)(1S,2R)-5-{3-[2-(2-Carboxyethylthio)-1-hydroxypentadeca-3(E),5(E)-dienyl]phenyl}-1H-tetrazole

The above compound was separated from the reaction described in Example11. MS(FAB) [M--H]⁻ 471.

(b)(1S,2R)-5-3-[2-(2-Carboxyethylthio)-1-hydroxypentadeca-3(E),5(E)-dienyl]phenyl}-1H-tetrazole,sodium salt.

A solution of the product of (a) (273 mg) was dissolved in 0.5M sodiumbicarbonate solution (1.16 ml) and the solution was freeze dried to givethe title compound as a pale solid.

EXAMPLE 13

(1S,2R)-3-[2-(2-Carboxyethylsulphinyl)-1-hydropentadeca-3(E),5(Z)-dienyl]benzoicacid

0.5M Sodium periodate solution (1.8 ml) was added to a stirred solutionof(1S,2R)-3-[2-(2-carboxyethylthio)-1-hydroxypentadeca-3(E),5(Z)-dienyl]benzoicacid (372 mg) in 0.5M sodium bicarbonate solution (3.2 ml) and methanol(3.2 ml) at 0°-5° C. The mixture was stirred for 1.5 hours at 0°-5° C.then further 0.5M sodium periodate solution (0.36 ml) was added. Themixture was stirred for a further 3 hours at 0°-5° C. then diluted withwater, acidified to pH3 and extracted with 3:1 dichloromethane:methanol.The extract was dried and evaporated to give the title compound as acrisp solid shown by reverse phase HPLC and nmr studies to contain twodiastereoisomeric sulphoxides in the ratio 2:1. MS(FAB) [M--H⁻ 463

EXAMPLE 14

(1S,2R)-5-{3-[2-(2-Carboxyethylsulphinyl)-1-hydroxypentadeca-3(E),5(E)dienyl]phenyl}1H-tetrazole

The above compound was prepared from(1S,2R)-5-{3-[2-(2-carboxyethylthio)-1-hydroxypentadeca-3(E),5(E)-dienyl]phenyl}-1H-tetrazoleby the process described in Example 13. The two diastereoisomers wereseparated by preparative reverse phase HPLC. MS (FAB) [M--H]⁻ 487

EXAMPLE 15

(1S,2R)-5-{3-[2-(2-Carboxyethylsulphonyl)-1-hydroxypentadeca-3(E),5(E)-dienyl]phenyl}-1H-tetrazole

A solution of potassium persulphate (150 mg) in water (0.5 ml) was addedto a stirred solution of(1S,2R)-5-{3-[2-(2-carboxyethylthio)-1-hydroxypentadeca-3(E),5(E)-dienyl]phenyl}-1H-tetrazole(50 mg) in 0.5M sodium bicarbonate solution (2 ml) and methanol (1 ml)at 0°-5° C. The mixture was stirred for 4 hours at 0°-5° C., dilutedwith water, acidified and extracted with 3:1 dichloromethane:methanol.The extract was dried and evaporated to give the title compound as acrisp solid. MS (FAB) [M--]⁻ 503.

EXAMPLES 16 AND 17

(1S,2R)-3-{2-(1H-Tetrazol-5-yl)ethylthio]-1-hydroxypentadeca-3(E),5(E)-dienyl}benzoicacid and 3(E),5(Z) isomer

(1S,2S)-3(1,2-Oxidopentadeca-3(E),5(Z)-dienyl)benzoic acid, methyl ester(1.78 g) prepared as in Example 4(a) was dissolved in a solution of3-thiopropionitrile (0.44 g) in methanol (5 ml) and triethylamine (0.5ml) under nitrogen. This clear solution was allowed to stand at roomtemperature for 6 hours and then evaporated to dryness. The resultantpale yellow oil was chromatographed on a silica column eluted withether/hexane 50/50. The required product(1S,2R)-3-{2-[2-cyanoethylthio]-1-hydroxypentadeca-3(E),5(Z)-dienyl}benzoicacid methyl ester (1.39 g) was obtained as a colourless oil.

This ester (1.25 g) was dissolved in tetrahydrofuran (10 ml) and 1Maqueous lithium hydroxide solution (3 ml) added. This solution was thenstirred overnight at room temperature under nitrogen. At the end of thisperiod further 1M aqueous lithium hydroxide solution (2 ml) was addedand the solution warmed to 30° C. for 3 hours. The solution was thenevaporated to remove the tetrahydrofuran and the remaining aqueoussolution was adjusted to a pH of 3 with 2M hydrochloric acid. Thissolution was then extracted 3 times with ether and the combined etherextracts dried (Mg₂ SO₄) and evaporated to an almost colourless oilwhich slowly crystallized at 0° C. to yield(1S,2R)-3-{2-[2-cyanoethyl]-1-hydroxypentadeca-3(E),5(Z)-dienyl}benzoicacid. This free acid (500 mg) was dissolved in dimethylformamide (10ml), sodium azide (2 g) and ammonium chloride (2 g) were added and thestirred suspension heated to 120° C. for 5.5 hours. At the end of thatperiod the mixture was diluted with water (30 ml) and the pH of thesolution adjusted to 3 with dilute hydrochloric acid prior to extractionfive times with ether. The ether extracts were dried (Mg₂ SO₄) andevaporated to a brown oil. The oil was dissolved in a mixture ofmethanol:water (85:15) and applied to a preparative reverse phase HPLCcolumn which was eluted with methanol:water (85:15) containing 0.5%acetic acid. The 3(E),5(Z) isomer of(1S,2R)-3-{2-[2-1H-tetrazol-5-yl)ethylthio]-1-hydroxypentadecadienyl}benzoicacid eluted first followed closely by the more abundant 3(E),5(E)isomer.

EXAMPLES 18-25

The compounds shown in the Table below were prepared using the processesdescribed in Example 3 with the appropriate thiols.

    ______________________________________                                         ##STR15##                                                                            R                                                                     ______________________________________                                                CH.sub.2 CO.sub.2 H                                                           CH(CH.sub.3)CO.sub.2 H                                                        CH(CH.sub.3)CH.sub.2 CO.sub.2 H                                               CH.sub.2 CH(CH.sub.3)CO.sub.2 H                                               (CH.sub.2).sub.3 CO.sub.2 H                                                   (CH.sub.2).sub.5 CO.sub.2 H                                                   CH(CH.sub.3)CONHCH.sub.2 CO.sub.2 H                                           (CH.sub.2).sub.2 CN                                                   ______________________________________                                    

EXAMPLE 26

(a) 3-(1,2-Oxidopentadeca-3(Z)-enyl)benzoic acid, Methyl ester

n-Butyl lithium (1.5M solution in hexane, 3.3 ml) was added dropwise toa stirred solution of dodecyltriphenyl phosphonium bromide (2.66 g) indry tetrahydrofuran (50 ml) at -70° C. under nitrogen. The deep orangesolution was stirred for 10 minutes at -70° C. then a solution of3-(2-formyl-1,2-oxidoethyl)benzoic acid, methyl ester (Example 1(b),1.03 g) in tetrahydrofuran (5 ml) was added. The pale suspension wasallowed to warm to room temperature, and evaporated and the residue wasextracted with 1:1 ether:hexane. The extract was evaporated and theresidue chromatographed on silica gel eluting with 1:1 ether:hexane. Thetitle compound was obtained as a colourless oil which solidified oncooling.

(b) Rel(1R,2S)-3-[2-(2-Carboxyethylthio)-1-hydroxypentadeca-3(Z)-enyl]benzoicacid

The above compound was prepared from the product of step (a) by theprocess described in Example 3.

EXAMPLES 27 AND 28

Rel(1R,2S)-3-[2-(2-Carboxyethylthio)-1-hydroxyundeca-3(E),5(Z)-dienyl]benzoicacid and

Rel(1R,2S)-3-[2-(2-carboxyethylthio)-1-hydroxynonadeca-3(E),5(Z)-dienyl]benzoicacid

The above compounds were prepared from the appropriate phosphoniumbromides by the processes described in Examples 1(d), 3(a) and 3(b).

EXAMPLE 29

(a) (8-Tetrahydropyranyloxyoctyl)triphenylphosphonium bromide

A solution of 1-bromo-8-tetrahydropyranyloxyoctane (9.8 g) and triphenylphosphine (8.8 g) in acetonitrile (50 ml) was heated under reflux for 8hours. The solution was evaporated and the residue washed with ether togive the title compound as a hygroscopic white solid which was dried byaddition of benzene and re-evaporation.

(b) 2-(11-Phenyl-8-undecenyloxy)-tetrahydropyran

n-Butyl lithium (1.6M solution in hexane, 20 ml) was added to a stirredsolution of the product of step (a) (11.0 g) in dry tetrahydrofuran at-70° C. under nitrogen. The orange solution was stirred for 30 minutesat -70° C. then a solution of 3-phenyl-propionaldehyde (2.75 g) intetrahydrofuran (7 ml) was added. The pale solution was allowed to warmto room temperature and then evaporated. The residue was extracted withether and the extract again evaporated and the residue waschromatographed on silica-gel eluting with 1:1 ether:hexane to give thetitle compound as a pale oil.

(c) 11-Phenyl-8-undecenol

A solution of the product of step (b) (8.7 g) in tetrahydrofuran (150ml) of 2M hydrochloric acid was stirred at room temperature for 4 hours.The mixture was neutralised with sodium bicarbonate solution andextracted with dichloromethane. Evaporation of the extract andchromatography of the residue on silica gel eluting with 1:1ether:hexane to remove starting material, then with ether, gave thetitle product as a pale oil.

(d) 11-Phenyl-8-undecenol tosylate

4-Toluenesulphonyl chloride (1.3 g) was added in portions to a stirredsolution of the product of step (c) (1.5 g) in pyridine at 0°-5° C. Themixture was stirred for 16 hours at 0°-5° C. then poured ontoice-hydrochloric acid and extracted with ether. The extract was washedwith sodium bicarbonate and sodium chloride solutions, dried andevaporated to give the title compound as a pale oil.

(1S,2S)-3-(1,2-Oxido-16-phenylhexadeca-3(E),5(Z),13(Z)-trienyl)benzoicacid, methyl ester

A solution of the product of step (d) (1.9 g) and triphenyl phosphine(1.3 g) in acetonitrile (20 ml) was heated under reflux for 48 hours.The solution was evaporated and the residue was washed with ether andfurther dried by addition of benzene and re-evaporation to leave thecrude phosphonium salt as a semi-solid mass.

n-Butyl lithium (1.6M solution in hexane, 1.5 ml) was added to a stirredsolution of this phosphonium salt in dry tetrahydrofuran (50 ml) at -70°C. under nitrogen. The deep yellow solution was stirred for 30 minutesat -70° C. then a solution of(1S,2S)-3-(4-formyl-1,2-oxidobut-3(E)-enyl)benzoic acid, methyl ester(Example 7(c)) (0.5 g) in tetrahydrofuran was added. The mixture wasallowed to warm to room temperature, evaporated and the residue wasextracted with 4:1 ether:dichloromethane. The extract was againevaporated and the residue was chromatographed on silica gel elutingwith 1:1 ether:hexane to give the title compound as a pale oil.

(f)(1S,2R)-3-[2-(2-Carboxyethylthio)-1-hydroxy-16-phenylhexadeca-3(E),5(Z),13(Z)-trienyl]benzoicacid

The above compound was prepared from the product of step (e) by theprocesses described in Example 3.

EXAMPLE 30

(a) 11-Phenyl-undecanol

A solution of 11-phenyl-8-undecenol (Example 29(c), 2.9 g) in ethanol(300 ml) was hydrogenated at 60 p.s.i. over 10% palladium on charcoal(0.6 g) for 1 hour. The catalyst was filtered off and the filtrate wasevaporated to give the title compound as a colourless oil.

(b) 11-Phenylundecanol tosylate

4-Toluenesulphonyl chloride (2.6 g) was added in portions to a stirredsolution of the product of step (a) (2.9 g) in pyridine (10 ml) at 0° C.The solution was stirred for 16 hours at 0°-5° C. then poured ontoice-hydrochloric acid and extracted with ether. The extract was washedwith sodium bicarbonate and sodium chloride solutions, dried andevaporated. The residue was chromatographed on silica gel eluting with1:1 dichloromethane:hexane to give the title compound as a colourlessoil.

(c)(1S,2R)-3-[2-(2-Carboxyethylthio)-1-hydroxy-16-phenylhexadeca-3(E),5(Z)-dienyl]benzoicacid

The above compound was prepared from the product of step (b) by theprocess described in examples 29(e) and 3.

EXAMPLES 31 AND 32

(1S,2R)-3-[(2-S-Glutathionyl)-1-hydroxypentadeca-3(E),5(E)dienyl]benzoicacid and its 3(E),5(Z) isomer

Glutathione (300 mg) was dissolved in a mixture of dry methanol (3 ml)and triethylamine (1 ml) and the solution added to(1S,2S)-3-(1,2-oxidopentadeca-3(E),5(Z)-dienyl]benzoic acid, methylester (prepared in Example 4(a)) under nitrogen. The resultant solutionwas allowed to stand at room temperature for 6 hours and the solventthen evaporated to dryness. Aqueous 2M lithium hydroxide solution (3 ml)was added and the solution stirred under nitrogen for 3 hours at roomtemperature. The pH of the solution was then adjusted to 4 with aceticacid and extracted with ether to remove non-polar impurities. Theaqueous solution was extracted 5 times with chloroform:methanol 1:1. Thecombined extracts were evaporated to dryness to give a crude mixture ofthe title compounds which were separated on a preparative reverse phaseHPLC column eluted with methanol:water 70:30 buffered with acetic acidand 0.88 ammonia to a pH of 5.3. The title compounds were pale yellowamorphous solids.

EXAMPLE 33

Rel (1R,2S)-3-(2-S-Cysteinyl-1-hydroxypentadeca-3(E),5(Z)-dienyl)benzoicacid, methyl ester

A solution of 3-(1,2-oxidopentadeca-3-(E),5(Z)-dienyl)benzoic acid,methyl ester (Example 1(d), 0.5 g), N-trifluoroacetylcysteine methylester (0.4 g) and triethylamine (0.5 ml) in dry methanol (2.0 ml) wasstored at room temperature for 3 days and then evaporated. The residuewas chromatographed on silica gel, eluting first with 1:1 ether:hexaneand then with ether to give the fully protected version of the titlecompound as a pale oil.

A solution of this compound (0.4 g) in methanol (7 ml) and 2M sodiumcarbonate solution (4 ml) was diluted with water to give a slighthaziness and then stored at room temperature for 30 hours. The solutionwas diluted with water (20 ml), acidified to pH4 and extracted withdichloromethane (3×15 ml). The extract was evaporated and the residuewas chromatographed on silica gel eluting with 1:1dichloromethane:methanol to give the title compound as a pale oil.

EXAMPLE 34

(a) 3-(6-Formyl-1,2-oxidohexa-3(E),5(E)-dienyl)benzoic acid, methylester

A solution of 3-(2-formyl-1,2-oxido-ethyl)benzoic acid, methyl ester(Example 1(b), 0.7 g) in dichloromethane (10 ml) was added over 1 hourto a stirred solution of triphenylphosphoranylidene-crotonaldehyde (1.5g) in dichloromethane (10 ml). The solution was stirred for a further1.5 hours and then evaporated and the residue was extracted with ether.The extract was evaporated and the residue was chromatographed on silicagel, eluting with ether to give a pale yellow oil containing the titlecompound mixed with the 3(Z),5(E) isomer. A solution of this mixture(230 mg) and iodine (10 mg) in dichloromethane (20 ml) was stirred for 2hours at room temperature and then evaporated. The residue was washedwith hexane to remove iodine, leaving the title compound as a yellowoil.

(b) 3-(1,2-Oxidohexadeca-3(E),5(E),7(Z),10(Z)-tetraenyl)benzoic acid,methyl ester

n-Butyl lithium (1.5M solution in hexane, 0.65 ml) was added slowly to astirred solution of 3-(Z)-nonenyltriphenylphosphonium tosylate (0.56 g)in dry tetrahydrofuran (5 ml) at -70° C. The dark orange-brown solutionwas stirred for 10 minutes at -70° C. then a solution of the product ofstep (a) (210 mg) in tetrahydrofuran (2 ml) was added. The mixture wasstirred for a further 15 minutes at 70° C., allowed to warm to roomtemperature and evaporated. The residue was chromatographed on silicagel eluting with 1:1 ether:hexane containing 1% triethylamine andfurther purified by HPLC to give the title compound as a pale oil.

(c) Rel(1R,2S)-3-[2-(2-Carboxyethylthio)-1-hydroxyhexadeca-3(E),5(E),7(Z),10(Z)-tetraenyl]benzoicacid, dimethyl ester

A solution of the product of step (b) (3 mg), methyl3-mercaptopropionate (2.4 μl) and triethylamine (5 μl) in dry methanol(100 μl) was stored at room temperature for 3 hours then the titlecompound was isolated by HPLC. MS M⁺ 486

(d) Rel(1R,2S)-3-[2-(2-carboxyethylthio)-1-hydroxyhexadeca-3(E),5(E),7(Z),10(Z)-tetracenyl]benzoicacid

A solution of the product of step (c) (2.2 mg) is methanol and 0.5Mpotassium carbonate solution was stored at room temperature for 16 hoursthen the title compound was isolated by reverse phase HPLC.

EXAMPLE 35

(a) 3-Mercaptopropionamide

Methyl 3-mercaptopropionate (1.2 g) was dissolved in 0.88 ammonia (75ml) and the solution stirred at 40° C. under nitrogen for 6 hours. Thesolution was then evaporated to dryness and the resultant white solidredissolved in dichloromethane this solution then being washed with 2Maqueous hydrochloric acid (10 ml) and dried (Mg₂ SO₄). This solutionupon evaporation yielded the title compound as white plates, m.p. 106°C., which were washed with ether.

(b)((1S,2R),-3-[2-(2-Carbamylethylthio)-1-hydroxypentadeca-3(E),5(Z)-dienyl]benzoicacid, methyl ester 3-Mercaptopropioamide (12 mg) was dissolved in drymethanol (200 μl) under nitrogen and triethylamine (100 μl) added. Thissolution was then added to (1S,2S)3(1,2-oxidopentadeca-3(E),5(Z)-dienyl)benzoic acid, methyl ester and theresultant solution allowed to stand at 40° C. for 3 hours. The solutionwas then evaporated to dryness and the residue chromatographed on asilica column eluted with ethyl acetate. The title compound was obtainedas off white crystals, m.p. 65°-67° C.

(c)(1S,2R)-3-[2-(2-carbamylethylthio)-1-hydroxypentadeca-3(E),5(Z)-dienyl]benzoicacid

A solution of the product of step (b)(40 mg) in tetrahydrofuran (2 ml)and M lithium hydroxide solution (0.2 ml) was stirred for 16 hours atroom temperature. Further M lithium hydroxide solution (0.2 ml) wasadded and the solution was stirred for a further 24 hours then dilutedwith water, acidified to pH 3 and extracted with dichloromethane. Theextract was dried and evaporated and the residue was further purified bypreparative reverse phase HPLC to give the title compound.

EXAMPLE 36

Rel(1R,2S)-3-[2-(2-Carboxyethylthio-1-hydroxypentadeca-3(E),5(E)-dienyl]benzoicacid

The product of Example 3(b) was shown by HPLC to contain about 10% of asecond component. Isolation of this minor component by reverse phaseHPLC on a C₁₈ Nucleosil column eluting with 80:20 methanol:waterbuffered to pH5.3 with acetic acid and ammonia gave the title compoundas a crystalline solid.

EXAMPLE 37

(a) 3-Cyanocinnamaldehyde

A suspension of active manganese dioxide (20 g) in a solution of3-cyanocinnamyl alcohol (Example 10(d), 4.0 g) in dichloromethane (100ml) was stirred at room temperature for 16 hours. The mixture wasfiltered and the filtrate was evaporated to give the title product as awhite solid, m.p. 100° C.

(b) 3(3-Cyanophenyl)-1,2-oxidopropanol

A solution of 3-cyanocinnamaldehyde (2.0 g) in methanol (20 ml) wasadded dropwise to a stirred solution of sodium bicarbonate (2.0 g) and50% hydrogen peroxide (1.0 ml) in water (10 ml). The solution wasstirred for 3 hours at room temperature then extracted withdichloromethane. The extract was dried and evaporated to give acolourless oil which was mainly the hemiacetal of the title aldehyde.

(c) 5-(3-Cyanophenyl)-4,5-oxido-2-pentenal

A mixture of the product of (b) and formylmethylenetriphenylphosphorane(3.0 g) in benzene (150 ml) was stirred at room temperature for 2 hoursthen filtered. The filtrate was evaporated and the residue was extractedwith ether. The extract was again evaporated and the residue waschromatographed on silica gel eluting with 3:1 ether-hexane to give thetitle compound as a pale oil.

(d) Rel (1R,2S)-3-(1,2-Oxido-pentadeca-3(E),5(Z)-dienyl) benzonitrile

The above compound was prepared from the product of step (c) by theprocess described in Example 1(d).

(e) Rel(1R,2S)-3-[2-(2-Carboxyethylthio)-1-hydroxypentadeca3(E),5(Z)-dienyl]benzonitrile,melthyl ester

The above compound was prepared from the product of step (d) by theprocess described in Example 3(a).

(f) Rel(1R,2S)-3-[2-(2-Carboxyethylthio)-1-hydroxypentadeca3(E),5(Z)-dienyl]benzonitrile

The above compound was prepared from the product of step (e) by theprocess described in Example 3(b).

(g) Rel(1R,2S)-5-{3-[2-(2-Carboxyethylthio)-1-hydroxypentadeca3(E),5(Z)-dienyl]phenyl}-1H-tetrazole

A mixture of the product of step (f) (100 mg), ammonium chloride (1.0 g)and sodium azide (1.0 g) in dimethylformamide (5 ml) was heated at 100°C. for 4 hours and then filtered. The filtrate was diluted with 2Mhydrochloric acid (50 ml) and extracted with dichloromethane. Theextract was evaporated to give a dark oil containing the title compoundand its 3(E),5(E) isomer in the ratio 40:60. The isomers were separatedby preparative reverse phase HPLC (on a LP₁ -ODS silica column elutingwith 85:15:0.1 methanol:wather:acetic acid) to give the title compoundas a crystalline solid, m.p. 153°-155° C. MS (FAB) M⁺ 473.

EXAMPLE 38

Rel(1R,2S)-{3-[2-(2-Carboxyethylthio)-1-hydroxypentadeca3(E),5(E)-dienyl]phenyl}-1H-tetrazole

The above compound was separated from the reaction described in Example37(g).

EXAMPLE 39

(a)(1R,2R)-3-[2-(3-Methoxycarbonylphenylthio)-1-hydroxypentadeca-3(E),5(Z)-dienyl]-dienyl]-benzoicacid, methyl ester

To a solution of methyl-3-mercaptobenzoate (0.42 g) in methanol (2 ml)under nitrogen was added triethylamine (0.38 ml) (development of lightyellow colouration). The mixture was then transferred to another flaskcontaining (1S,2S)-3-[1,2-oxido-pentadeca-3(E),5(Z)-dienyl]benzoic acid,methyl ester (0.8 g) under nitrogen. The reaction mixture was stirred atroom temperature under nitrogen for 2 hours.

The volatiles were removed under a nitrogen stream and the residual oilpurified by column chromatography (silica; eluant hexane 50% diethylether), to give the product as a light-yellow oil. (Proton NMR indicatespredominantly (E),(Z) stereochemistry).

(b)(1S,2R)-3-[2-(3-Carboxyphenylthio)-1-hydroxypentadeca3(E),5(Z)-dienyl]benzoicacid

To a solution of the diester (from step (a) (0.46 g) in tetrahydrofuran(2 ml) was added 2M lithium hydroxide solution (2.6 ml). The biphasicsystem was stirred vigorously for 20 hours at room temperature.

The tetrahydrofuran was removed in vacuo, and the aqueous phasecautiously acidified to pH4 with 2M hydrochloric acid. Extraction withchloroform, followed by drying (magnesium sulphate) and evaporation gavethe title compound as a light-yellow solid, m.p. 90° (withresinification)

EXAMPLES 40-42

Similarly prepared, by the methods of Example 39 were the following:

(1S,2R)-3-[2-(4-Carboxyphenylthio)-1-hydroxypentadeca-3(E),5(Z)dienyl]benxoic acid (sticky yellow solid).

(1S,2R)-3-[2-(2-Carboxyphenylthio)-1-hydroxypentadeca-3(E),5(Z)-dienyl]benzoicacid (sticky solid).

(1S,2R)-3-[2-(butylthio)-1-hydroxypentadeca-3(E),5(Z)-dienyl]benzoicacid.

EXAMPLE 43

(a)(1S,2R)-3-[1-(3-Cyanophenyl)-1-hydroxypentadeca-3(E),5(Z)-dien-2-ylthio]benzoicacid, methyl ester

To a solution of methyl-3-mercaptobenzoate (0.29 g) in methanol (1 ml)under nitrogen was added triethylamine (0.26 ml) (development of yellowcolouration). The mixture was then added to(1S,2S)-3-(1-oxidopentadeca-3(E),5(Z)-dienyl)benzonitrile (0.5 g) undernitrogen, and the reaction mixture stirred at room temperature for 4hours.

The volatiles were removed under a nitrogen stream and the residual oilpurified by chromatography (silica; eluant hexane/ether) to yield theproduct as a yellow oil.

(b)(1S,2R)-3-[1-(3-Cyanophenyl)-1-hydroxypentadeca-3(E),5(Z)dien-2-ylthio]benzoicacid

To a solution of the methyl ester from step (a) (50 mg) intetrahydrofuran (0.3 ml) was added 2M lithium hydroxide solution (0.15ml), and the mixture stirred at room temperature for 24 hours.

The tetrahydrofuran was evaporated in vacuo, the aqueous phase acidifiedwith 2M hydrochloric acid, and extracted twice with dichloromethane.Drying (magnesium sulphate) and evaporation of the organic extracts gavethe title compound as a light-amber oil. (Proton NMR and reverse phaseHPLC indicate about 30% of the (E),(E) isomer present.)

EXAMPLE 44

(a) 2,3-Oxido-3-phenylpropionaldehyde

To 50% hydrogen peroxide solution (16 ml), buffered with saturatedsodium hydrogen carbonate solution) was added dropwise, with ice-bathcooling, a solution of cinnamaldehyde (26.4 g) in methanol (100 ml). Themixture was stirred at room temperature for 4 hours.

The methanol was removed in vacuo, and the aqueous phase extracted twicewith toluene. The dried extracts were used, without isolation of thetitle compound, directly in step (b).

(b) 4,5-Oxido-5-phenyl-2-pentenal

The solution of 2,3-oxido-3-phenylpropionaldehyde in dry toluene (300ml) from step (a) was treated with formylmethylene triphenyl phosphorane(60.8 g) and the mixture stirred at room temperature for 20 hours.

The reaction mixture was filtered and evaporated in vacuo, and theresidual solid extracted three times with ether using an ultrasonicbath. The ether extracts were filtered and evaporated to give an oilwhich was further purified by column chromatography (silica; eluanthexane:ether, 1:1) to give the product as a yellow oil.

(c) 1,2-Oxido-1-phenylpentadeca-3(E),5(Z) -diene

To a solution of n-decyl-triphenylphosphonium bromide (20.54 g) in drytetrahydrofuran (200 ml), cooled to -70° C. (dry ice/acetone bath) undernitrogen was added n-butyl lithium (26.6 ml of 1.6M hexane solution).There was immediate generation of orange colour of ylid. The mixture wasstirred for 10 minutes, then a solution of 4,5-oxido-5-phenyl-2-pentenal(from step (b) in dry tetrahydrofuran (100 ml) added. The reactionmixture was allowed to warm to room temperature and stirred for 2 hours.

The tetrahydrofuran was evaporated in vacuo, the residual semi-solidextracted four times with diethyl ether using ultrasonification, and theextracts filtered and evaporated to give a yellow oil. This oil wasfurther purified by chromatography (silica; eluant hexane:water, 1:1) togive the product as a mobile yellow oil, which crystallised upon coolingto -20° C. (m.p. <50° C.).

(d) Rel(1R,2S)-2-(2-Methoxycarbonylethylthio)-1-hydroxy-1-phenylpentadeca-3(E),5(Z)-diene

To a solution of methyl-3-mercaptopropionate (0.44 g) in methanol (2 ml)under nitrogen was added triethylamine (0.5 ml). The mixture wastransferred to a flask containing the epoxide from step (c) (1.00 g)under nitrogen. The reaction mixture was stirred for 20 hours, thenfurther thiol (0.44 g) and triethylamine (0.5 ml) added.

After an additional 20 hours at room temperature the volatiles wereremoved under a nitrogen stream and the residue subjected to columnchromatography (silica; eluant hexane:diethyl ether, 3:1), to give thetitle compound as a colourless oil.

(e) Rel(1R,2S)-2-(2-Carboxyethylthio)-1-hydroxy-1-phenylpentadeca-3(E),5(Z)-diene

A mixture of the methyl ester from step (d) (0.49 g) tetrahydrofuran (3ml) and 1M lithium hydroxide solution (3.5 ml) was stirred at roomtemperature for 24 hours.

The tetrahydrofuran was evaporated in vacuo, the aqueous phase acidifiedwith 2M hydrochloric acid, and extracted twice with diethyl ether. Thecombined organic extracts were dried (magnesium sulphate) and evaporatedto give the title compound as an amber oil.

EXAMPLE 45 (Alternative method)

(a) 3-[3-(2-Triphenylmethyl-2H-tetrazol-5-yl)phenyl]-2-propenol

To a solution of 3-[3-(1H-tetrazol-5-yl)phenyl]-2-propenol (2.02 g) indry dichloromethane (50 ml) was added triethylamine (1.5 ml) followed bytriphenylchloromethane (2.8 g) in dry dichlormethane. The solution wasstirred at room temperature for 90 minutes, washed with water (50 ml),followed by sodium bicarbonate solution (5%; 50 ml), dried overmagnesium sulphate, filtered and evaporated under reduced pressure togive a pale brown viscous oil which crystallised on standing to a creamsolid.

(2S,3S)-3-[3-(2-Triphenylmethyl-2H-tetrazol-5-yl)phenyl]2,3-oxidopropanol

L-(+)-Dimethyl tartrate (1.85 g) was added in dry dichloromethane (10ml) dropwise to a stirred solution of titanium (IV) isopropoxide (3.1ml) in dry dichloromethane (30 ml) at -20° to -25° C. under nitrogen.The solution was stirred for 10 minutes and a solution of3-[3-(2-triphenylmethyl-2H-tetrazol-5-yl)phenyl]-2-propenol (4.5 g) indry dichlormethane (20 ml) was added, followed by a 3.7M solution oft-butylhydroperoxide in toluene (6.7 ml), both at -20° to -25° C. Thepale orange solution was left to stand in a freezer for 3 hours. To thestirred solution was added aqueous tartaric acid (10%; 50 ml) and themixture stirred for 1 hours, filtered and separated. The dichloromethanelayer was dried over magnesium sulphate filtered and evaporated underreduced pressure to give a yellow oil. The oil was dissolved in carbontetrachloride, washed with water, dried over magnesium sulphate,filtered and evaporated under reduced pressure to give a pale yellowoil. The oil was chromatographed on a silica gel column using diethylether and hexane (2:1) and the required fractions evaporated underreduced pressure to give a colourless crystalline solid.

(c)(4S,5S)-5-[3-(2-Triphenylmethyl-2H-tetrazol-5-yl)phenyl]-4,5-oxido-2-pentenal

Solid-chromium trioxide (5.0 g) was added to a stirred solution ofpyridine (7.9 ml) in dry dichloromethane (200 ml) at 5° C. The mixturewas stirred for 45 minutes, warming to 13° C., allowing all the chromiumtrioxide to dissolve, then a solution of the epoxyalcohol of step (b)(4.61 g) in dry dichloromethane (50 ml) was added rapidly. The darkmixture was stirred for 90 minutes, warming to room temperature, thenfiltered through a pad of Florisil to remove the chromium salts, and thecolourless filtrate was evaporated under reduced pressure to leave apale yellow oil.

To a solution of the oil (1.8 g) in benzene (75 ml) under nitrogen, wasadded formylmethylenetriphenylphosphorane (1.34 g) in one portion. Thesuspension was stirred at room temperature under nitrogen for eighthours, unreacted ylid was filtered off and the filtrate evaporated underreduced pressure to a brown oil. The brown oil was extracted with hotether, cooled, filtered and evaporated under reduced pressure to give ayellow oil, which crystallised on standing to give a yellow solid.

(d) (1S,2S)-5-{3-[2-(1,2-Oxido)pentadeca-3(E),5(Z)-dienyl]phenyl}-2-triphenylmethyl-2H-tetrazole

n-Butyl lithium (8.91 ml; 1.5M) in hexane was added dropwise to astirred solution of n-decyl triphenylphosphonium bromide (6.07 g) (driedat 80° C. under reduced pressure for 16 hours) in dry tetrahydrofuran(130 ml) at -70° C. under nitrogen. The clear deep orange solutionobtained was stirred for a further 10 minutes at -70° C., then asolution of5-[3-(2-triphenylmethyl-2H-tetrazol-5-yl)phenyl]-4,5-oxido-2-pentenal(6.4 g) in dry tetrahydrofuran (75 ml) was added dropwise. The paleyellow solution was stirred at -70° C. for 1 hour, allowed to warm atroom temperature and evaporated under reduced pressure to a brown oil.The oil was extracted with ether:hexane (1:2; 4×200 ml) and the palehazy extract evaporated under reduced pressure to give the titlecompound as a yellow oil.

(e)(1S,2R)-5-{3-[2-(2-Methoxycarbonylethylthio)-1-hydroxypentadeca-3(E),5(Z)-dienyl]phenyl}-2-triphenylmethyl-2H-tetrazole.

A solution of(1S,2S)-5-{3-[2-(1,2-oxido)pentadec-3(E),5(Z)-dienyl]phenyl}-2-triphenylmethyl-2H-tetrazole(4.5 g) and triethylamine (2.06 ml) in methanol (15 ml) was placed in aflask under nitrogen. This solution was then added to methyl3-thiopropionate (900 mg) under nitrogen and the solution was thenstirred for 24 hours at room temperature until reaction was complete.The solution was evaporated under reduced pressure to leave a brown oilwhich was chromatographed on a silica column using ether:hexane (1:1).The required fractions were evaporated under reduced pressure to givethe title compound as a yellow oil.

(f)(1S,2R)-5-{3-[2-(2-Carboxyethylthio)-1-hydroxypentadeca-3(E),5(Z)-dienyl]phenyl}-1H-tetrazole,sodium salt

(1S,2R)-5-{3-[2-Methoxycarbonylethylthio)-1-hydroxypentadeca-3(E),5(Z)-dienyl]phenyl}-2-triphenylmethyl-2H-tetrazole(2.74 g) was dissolved in ether (50 ml) to which was added aqueoushydrochloric acid (20 ml; 5M) and the mixture stirred at roomtemperature for 4 hours, when t.l.c. showed the loss of triphenylmethylprotection was completed. The ether was evaporated under reducedpressure, tetrahydrofuran (30 ml) was added, followed by the addition ofaqueous lithium hydroxide (2M) until the solution was alkaline. Themixture was then left to stir overnight at room temperature. The aqueousbasic phase was then separated, acidified with aqueous hydrochloric acid(2M), extracted with ether (2×50 ml) and the ether extract evaporatedunder reduced pressure to give a brown oil. The oil was chromatographedon a silica column using ether and the required fraction evaporatedunder reduced pressure to give a pale yellow oil. The oil was dissolvedin aqueous sodium bicarbonate (0.5M; 1 eq) and freeze-dried to give thesodium salt.

In the formulating the active compounds of the invention, they arepreferably employed in salt form. The following formulations are givenby way of example:

EXAMPLE 46

Soft gelatin capsule

Each soft gelatin capsule contains:

    ______________________________________                                        Active ingredient                                                                              150 mg                                                       Arachis oil      150 mg                                                       ______________________________________                                    

After mixing together, the blend is filled into soft gelatin capsulesusing the appropriate equipment.

EXAMPLE 47

Hard gelatin capsule

Each capsule contains

    ______________________________________                                        Active ingredient                                                                               50 mg                                                       PEG 4000         250 mg                                                       ______________________________________                                    

The PEG 4000 is melted and mixed with the active ingredient. Whilststill molten the mixture is filled into capsule shells and allowed tocool.

EXAMPLE 48

Aerosol

    ______________________________________                                        Active ingredient         10 mg                                               Ethanol                   50 mg                                               Dichlorodifluoromethane (Propellant 12)                                                                658 mg                                               Dichlorotetrafluoroethane (Propellant 114)                                                             282 mg                                               ______________________________________                                    

The active ingredient is dissolved in the ethanol. The concentrate isfilled into extruded aluminum cans for inhalation aerosols. The cans aredegassed with propellant 12 and sealed with an appropriate metered dosevalve. The volume of product expelled per actuation is 50 to 100 μlequivalent to 0.5-1 mg active ingredient.

We claim:
 1. A compound of the formula ##STR16## ps in which R¹ is analkenyl or alkynyl group .Iadd.containing from 10 to 20 carbon atoms and.Iaddend.optionally substituted with a phenyl group or phenyl groupsubstituted with 1-3 substituents selected from the group consisting ofC₁ -C₄ alkyl, C₁ -C₄ alkoxy, hydroxy, nitro, cyano, halo,trifluoromethyl, carboxyl, tetrazolyl, and --CONH₂, .[.and containingfrom 5 to 30 carbon atoms,.]. and R³, R⁴ and R⁵ are each selected fromhydrogen, carboxyl, C₂ -C₅ alkoxycarbonyl, C₁ C₄ alkyl, C₁ -C₄ alkoxy,hydroxyl, tetrazolyl, tetrazolyl protected with a trityl or benzhydrylgroup, halo, trifluoromethyl, nitrile, nitro and CONR₂ ¹⁰ where each R¹⁰is hydrogen or C₁ -C₄ alkyl; and salts thereof.
 2. The compound of claim1 which is(1S,2S)-5-{3-[2-(1,2-oxido)pentadeca-3(E),5(Z)-dienyl]phenyl}-2-triphenylmethyl-2H-tetrazole.